Friction clutch



March 3, 1942. c. A. RUESENBERG ETAL 2,275,068

FRICTION CLUTCH Filed May 6, 1939 2 Sheets-Sheet l @W @jp/47% 62 gf i? March 3, 1942. c. A. RUESENBERG ETAL 2,275,068

FRIGTION CLUTCH FfiledvMay 6, 1939 2 Sheets-Sheet 2 Patented Mar. 3, 1942 UNITED fsTATEs PATENT oFFlci-J FRICTION CLUTCH Carl A. Ruesenberg and Joseph Patkus, Rockford, lll., assignors to Borg-Warner Corporation, Chicago, Ill., a corporation of Illinois Application May 6, 1939, Serial No. 272,092

11 claims.

As an illustration of one form in which the invention may be embodied, we have shown in Figs. 1 and 2 an automatic clutch wherein a conventional drive plate IIJ, including friction facings II, is adapted to be packed between a 4 pair of clutch members, one of which comprises elements amount to only a fraction of the total l force applied to the pressure plate for clutch packing, the packing pressure being derived fromv said centrifugal forces by force multiplying mechanism interposed between the centrifugal elements and the pressure plates, and the manual trifugal elements in order to neutralize the packing pressure.

Another object of the invention is to provide a novel and improved means for effecting adjustment between the centrifugal elements and the pressure plate, in an arrangement of the general type mentioned above. The invention contemplates, in this respect, making it possible to quickly effect fine adjustments between the centrifugal element and the pressure plate so as to compensate for facing wear, etc., Without affecting the function of the manual release means.

.A4 further object of the invention is to provide a novel and improved type of yielding means for transmitting to the pressure plate all forces received through the force multiplying mechanism from `the centrifugal elements.

The above and other objects, advantages and uses of our invrtion will become more apparent from a reading of the following specification and claims taken in connection with the appended drawings which form a part of this specification and wherein:

Fig. 1 is a rear elevation of a clutch embodying the invention, parts being broken away to better illustrate the construction;

Fig. 2 is an axial sectional view of the`same taken as indicated by the line 2-2 of Fig. 1;

Fig. 3 is a detailed tangential sectional view, taken as indicated by the line 3-3 of Fig. 1; illustrating the force multiplying mechanism; and

Fig. 4 is an axiai' sectional view of a clutch.

embodying a modified form of the invention.

the flywheel I2 of the engine to which the clutch is applied, and the other of which comprises the conventional pressure plate I3. To the flywheel I2j may be secured, as by cap screws I4, the cover plate I5 which serves as a reaction lmember upon which may be fulcrumed the centrifugal elements I6.

The centrifugal elements I6 are preferably in the form of levers disposedroughly in radial positions with their outer arms provided with weights I'I and their inner arms I8 projecting radially inwardly from a fulcrum pin I 9 upon which they are mounted. The pins I9 may be mou'nted in spaced ears 20, and each lever may be received between a pair of the ears 20.

The driven shaft 2|, which may be splined in a conventional manner in the hub 22 of the driven plate IIJ, extends through a bushing 23 which is mounted in the cover plate I5 and projects rearwardly therefrom. Axiaily slidable on the bushing 23 is an intermediate member in the form of a sleeve .24 encircling the bushing 23, and serving the-double purpose, first of transu mitting from the centrifugal elements I6 to the .torce multiplying mechanism (designated generally at 2'5) the centrifugal forces developed in the elements I6, and, second, of transmitting directly to the centrifugal elements I6 pressure from the manual release means which may include a conventional release fork 26 and release collar 2l.

The sleeve 24 is connected to the inner arms I8. of the levers I6, by means of links 28, each pivoted at one end on a pin 29 between the bifurcations of a respective lever arm I8 and at its other end on a pin 33 between a pair of ears 3 I formed on the sleeve 24.

Each of the force multiplying devices 25 comprises an elongated cylindrical cam member 32V major axis of the clutch. The high regions of the cam heads 33 are defined by anti-friction rollers 34 loosely socketed in recesses 35 in the heads 33. The rollers 3l 'are retained in the recesses 35 by end plates 36 secured at 31 to the pressure plate I3 and disposed in embracing, con

ning relationship to the respective ends of the cam member 32.

through openings 56 in the respective springs.` Thus the springs 39 are located against tangential displacement.

'I'he cam element 32 and the spring 39 are retained against radial displacement by pairs of lugs 4t whichare-shaped so as to snugly receive the spring 39 between their base portions and flared outwardly so as to form bearing surfaces for coaction with the cylindrical bearing surfaces 4l of the cam heads 33.

Each cam element 32 is formed, intermediate its ends, with a radially projecting integral lever d2 projecting toward the major axis of the clutch and formed at its inner end with a fork d3. A

pull link lll is pivoted on a pin d5 in a respective fork 43, and extends axially through an'opening 4t in the cover plate 62, its other end being pivoted on a pin M between a pair of ears it formed on the forward end of the sleeve 2d.

The pressure plate i3 is urged away from the driven plate Il@ by means of retractor springs d@ each attached at one end to an ear 53 formed on the sleeve 2t, extending through an opening 5l in the cover plate l5, and attached at its other end to an ear 52 on the pressure plate i3.

The cover plate I5 is made in several parts which are adjustable relative to each other in order to provide for adjustment between the cover plate, the pressure plate I3, and the force multiplying mechanism 25. IThese parts include a rim portion Gil, which is attached directly to the flywheel l2, and which has an axially extending flange 6i, a reaction plate 62 in which the hardened bearing link 38 is mounted, and' which is axially slidable within the flange 6I, and an adjusting collar 63 engaging against the reaction plate 62 and having a rim flange 64which is threaded upon the flange 6I. Rotation of the collar 63 on its threaded connection with the flange 6I will cause it to move axially, thereby varying the axial position at which it supports the central disc portion 62 against pressure of the cam heads 33.

The disc portion 62 is located against rotation relative to the rim portion 60, by means of studs 65 mounted in the flange 6I and engaged in notches 66 (Fig. 1) in the disc portion 62. The collar 63 is locked against unscrewing by clamping lugs 61 and clamping screws 68 threaded into the disc portion 62.

In the operation of the clutch, the retractorl springs 49 will hold the clutch disengaged when the engine is not operating. When the engine is running, the cover plate I5, which is rigidly associated with the flywheel I2 of the engine, will carry the centrifugal elements I6 in a circular orbit, thus causing centrifugal force to bef developed in the weighted outer portions I1 thereof, which project at an angle between an axial and a radial direction..

The centrifugal force thus developed in the centrifugal elements I6 will be transmitting through the thrust links 28 to the sleeve 24 and from the sleeve 24 through the pull links 44 to the levers 42 of the cam elements 32, tending to rotate the cam heads 33 in a direction (clockwise as viewed in Fig. 2) to exert expanding pressure between the cover plate I5 and the pressure plate I3. The rollers 34vprovide the contact with the springs 39 and the hardened ring 38 respectively, thus largely eliminating friction as a factor in the automatic operation of the device.

The maximum pressure which ca n be transmitted to the pressure plate I3 is determined by the resistance of the leaf springs 39. When such maximum pressure has been attained, any further increase in centrifugal force developed in the centrifugal elements I6 will result in compression of the springs 39, allowing the weights Il! to move further outwardly toward more truly radial positions, and thereby tending to maintain the centrifugal force at an even level.

When it is desired to release the clutch manually, the manual control element, which may or may not be a conventional clutch pedal, is depressed, causing the fork 26 to move fore wardly and transmit pressure to the sleeve 24 through the medium of the collar 2li, in opposition to thel pressure transmitted to the sleeve 24 by the centrifugal elements i6. Thus it is necessary to overcome only the pressure developed in the centrifugal elements it, the total of which is only a fractional portion of the amount of pressure developed between the pressure plate'- l3 and cover plate lby the force multiplying devices 25.

In Fig. 4 is shown an automatic clutch without a manual overcontrol, embodying the principles of construction and arrangement of the invention with respect 'to the centrifugal elements, the force multiplying means, and the connecting linkage. These parts are all the same as in the preferred form of the invention, and are referred to by the same reference characters, with the exception of the pull links 64a, which are pivoted directly to the inner ends of the arms it of the centrifugal elements, as at 29a, the sleeve 2G and manual release mechanism being eliminated. The operation of this clutch is the same as the preferred form of the clutch, with the exception that it does not embody the manual release.

We claim:

1. In a centrifugal clutch, a pair of clutch members between which a clutch part is adapted .to be packed, a plurality of centrifugal force responsive weighted levers fulcrumed on one of said members, an exially movable sleeve, coaxial with the major axis of the clutch, links connecting said sleeve to each of said levers so as to transmit to said sleeve the centrifugal forces developed in said levers, force multiplying mechanism interposed between said sleeve and the other clutch member, adapted to transmit to the latter, in multiplied amount, the pressure received from said sleeve, comprising an axially extending link pivoted at one end to said force-multiplying mechanism, extending through said cover plate, and pivoted at its other end to said sleeve, and manual release means for applying manual pressure directly to said sleeve in opposition to said centrifugal forces.

2. In a centrifugal clutch, a pressure plate, a cover plate, a plurality of levers, weighted at their outer ends and fulcrumed on said cover plate for swinging movement' in radial planes, a driven shaft, an axially movable sleeve through which said shaft extends, axially extending links pivoted to the inner ends of said levers and to said sleeve, for transmitting to the latter the centriugal forces developed in said levers, force multiplying cam devices operatively interposed between said sleeve and said pressure plate, adapted to transmit to said pressure plate, in multiplied amount, the pressure received from said sleeve, comprising a plurality of symmetrically spaced axially extending links each pivoted at one end to a corresponding cam lever, .extending through the cover plate, and pivoted at itsother end to said sleeve, and manual release means for applying manual pressure directly to said sleeve in opposition to said centrifugal forces.

3. In a centrifugal clutch, a pressure plate, a cover plate, a plurality of centrifugal force responsive elements movably mounted on said cover plate, a driven shaft, a sleeve through which said shaft extends, said sleeve being axially slidable and adapted to receive from said elements the centrifugal forces developed therein, force multiplying cam devices interposed between said pressure plate and said cover plate, each of said cam devices being provided with a radially extending operating lever, axially extending links each pivoted at one end to a corresponding cam lever, extending through said cover plate, and pivoted at its other end to said sleeve, and means for applying manual pressure directly to said sleeve in opposition to said centrifugal forces.

4. In a centrifugal clutch, a pressure plate, a cover plate, a plurality of levers, weighted at their outer ends and fulcrumed on said cover plate for swinging movement in radial planes, force multiplying cam devices interposed between said pressure plate and said covery plate, each of said devices being provided with a-radially inwardly extending lever, and means for transmitting from the inner ends of said weighted levers to the inner ends of said cam levers, the centrifugal forces developed in said weighted levers, said means including axially extending links extending through saidcover plate and pivoted to said cam levers.

5. In a friction clutch, a pressure plate, a cover plate and means for spreading said plates, said means including a plurality of circumferentially spaced, tangentially disposed, bowed leaf spring elements, the ends of which are in engagement with the pressure plate, elongated cam devices interposed between said cover plate and said spring elements, parallel to the latter,

- and means for rotating said cam elements to effect the spreading movement.

6. In a friction clutch, a pressure plate, a cover plate and means for spreading said plates, said means including a plurality of circumferentially spaced, tangentially bowed leaf spring elements, the ends of which are in engagement with the pressure plate, elongated cam devices interposed between said cover plate and said spring elements, parallel to the latter, and centrifugal force responsive means for rotating said cam elements to effect the spreading movement.

7. In a centrifugal clutch, a pressure plate, a cover plate, a plurality of centrifugal force responsive elements movably mounted on said cover plate, a driven shaft, a sleeve through which said shaft extends, said sleeve being axially slidable and adapted to receive from said elements the centrifugal forces developed therein, a plurality of circumferentially spaced, tangentially disposed, bowed leaf springs, the ends of which are in engagement with the pressure plate, elongated cam devices interposed between the cover plate and said spring elements, and

means actuated by said sleeve under the effect of said centrifugal forces for rotating said cam devices so as to spread said plates.

8. In a friction clutch, a pressure plate, a

cover plate, and means for spreading said plates,

said means including a plurality of circumfer- Aentially spaced cushioning elements carried by the pressure plate, cam devices interposed between the cover plate and the pressure plate, in

engagement .with the cover plate and said cush- V ioning elements, and means for rotating said cam devices to effect spreading movement between said cover plate and said pressure plate. v

9. In a friction clutch, a flywheel provided with an axially projecting externally threaded annular flange, a pressure plate, areaction plate piloted within said flange-and having an axially slidable and non-rotatable connection therewith, centrifugal clutch packing mechanism carried by said reaction plate, means for transferring the centrifugal pressure to the pressure plate, and means for adjusting said reaction plate relative to said pressure plate, comprising a collar threadably embracing said flange, said collar having a radially inwardly disposed flange portion engaging said reaction plate.

1o. A friction clutch as defined'in claim s, wherein said cushion elements comprise bowed CARL A. RUESENBERG.

JOSEPH PATKUS. 

